A belief system that gives itself the trappings of a science when it actually doesn't adhere much to the scientific method. Can range from something as mild as cryptozoology ("monster hunting", which has its heart in the right place but is far too uncritical of things) to various New Age beliefs, creationism, alternative medicine, etc. etc.

My friend went to a chiropractor, but after he found out that the whole field was a psuedoscience he decided to get massages at home.